Vacuum relay



V. E. DE LUCIA VACUUM RELAY May 6, i969 Filed June 5, 1967 United States Patent O U.S. Cl. 200--144 6 Claims ABSTRACT OF THE DISCLOSURE An improved vacuum relay wherein a movable contact is rotated angularly about the axis of the terminal to which said contact is pivotally connected.

CROSS REFERENCE TO A RELATED APPLICATION Copending application Ser. No. 544,480 filed Apr. 22, 1966, describes and claims an improved ceramic vacuum relay of the general type with which the present invention is concerned.

BACKGROUND OF THE INVENTION The improved vacuum relay of the copending application mentioned above is capable of switching high voltage, high frequency signals at a relatively high rate for prolonged periods of time, and of achieving this without any material deterioration of the relay contacts. The vacuum relay of the present invention is also capable of such desired operation. The present relay, like the relay of the copending application, is advantageous in that it is simple in its construction. In addition, the relay of the invention exhibits high magnetic efiiciency in that it exhibits a high armature pull-in force with relatively low energizing arnpere-turns.

A particular feature of the relay of the present invention is the configuration and mounting of the movable contact. As will also be described, the configuration of the movable contact is such that a large contact area is provided in a simple manner, this resulting in a desired low contact resistance in the relay.

The relay is constructed, as will be described, in two distinct portions, each of which can be adjusted independently of the other. The two portions are then brought together and welded, for example, as a final step in the production of the relay.

The `armature of the relay, in the illustrated embodiment, is coupled to the movable contact by means of an insulating rod composed, for example, of sapphire. The armature is pivotally mounted in the relay, and the rod extends essentially perpendicularly to the plane of the armature. This rod exhibits some limited measure of resilient angular movement; so as to permit the relay to be assembled without the need to meet excessively close tolerances, and to provide for smoother and more efficient relay operation.

SUMMARY OF THE INVENTION The invention provides an improved vacuum relay for switching high frequency currents. The switching elements are mounted in a vacuum envelope composed, for example, of a ceramic material. The movable contact is configured to define a hollow rectangle, so as to provide lan optimum configuration for resisting distortion at high temperatures. An insulating rod couples the relay armature to the movable contact, and the rod extends up into a bracket in the bottom of the hollow rectangle defined by the movable contact. A separate biasing spring may be provided, which is coupled to the movable contact and which biases it away from one of the fixed contacts of the 3,443,046 Patented May 6, 1969 ICC relay and, for example, against another fixed contact, in a single-pole double-throw assembly. The sapphire rod, on the other hand, when the armature is actuated, moves the movable contact towards the other fixed contact against the `bias of the biasing spring. When the relay is de-energized, the aforesaid biasing spring returns the movable contact to the first fixed contact, and there is no need for the insulating rod to pull the armature back to that contact. This means that when such a separate biasing spring is used, the armature spring, itself, may be very weak, and just strong enough to push the weight of the armature up to the vde-energized position.

BRIEF DESCRIPTION OF THE DRAWING PREFERRED EMBODIMENT OF THE INVENTION The relay illustrated in the drawing is a single-pole double-throw type. It includes a tubular-shaped envelope 10. The envelope 10 may be composed of ceramic, or other appropriate material exhibiting low leakage loss to high frequency electrical currents.

The envelope 10 has a cup-shaped configuration in the illustrated embodiment so .as to have a closed top and an open bottom, as best shown in FIGURES 1 and 4. Three electrically conductive terminal pins 12, 14 and 16 extend into the envelope 10 through its closed top for single-pole double-throw operation. These pins may be in the form, for example, of copper rods. It will be evident as the description proceeds that the concepts of the invention are not limited to single-pole double-throw operation.

A ring-shaped flange member 20 is attached to the lower end of the envelope 10, and a magnetic member 18 is attached to the flange member 20 by means, for example, of heliarc welding, brazing or the like. The member 20 is sealed to the envelope 10 by known techniques. The magnetic member 18 serves as a closure for the open lower end of the envelope 10, and it also serves as a pole piece for the magnetic circuit of the relay. The magnetic member 18 may be formed, for example, of a suitable magnetic material such as soft iron; and the ring member 20 may be formed of a suitable material matching the expansion of the envelope, the material, for example, may be that presently available under the trade name Kovar.

An annular closure, or wall, member 22 is welded, or otherwise affixed, to the outer face of the magnetic member 18 in concentric relationship therewith. The annular member 22 may be vcomposed of any suitable nonmag netic material, such as Monel metal. An elongated tubular core member 24 is welded, or otherwise affixed to the annular mme-ber 22, and the core member extends through the annular member and awa-y from the outer face of the wall 18, as shown in FIGURE 2. The core member 24, likewise, is composed of suitable magnetic material such as soft iron.

A passage is provided through the core member 24 along its longitudinal axis. This passage extends to the interior of the envelope 10. A tube 26 is disposed in the passage, and the tube protrudes down beyond the end of the core 24, as best shown in FIGURE 3. The tube 26, as in the relay described in the aforesaid copending application, provides a convenient means for evacuating and out-gassing the interior of the envelope 10. After evacuation and out-gassing, the lower end of the tube is sealed, as shown in FIGURES 1 and 3.

The energizing coil 30 for the assembly is supported on a disc-like base 32 (FIGURES 3 and 4), and terminal pins 31 and 33 for the coil extend through the base. The coil 30 is supported within a tubular housing 40 which likewise is composed of a suitable magnetic material such as soft iron. The base 32 is also composed of magnetic material, so as to complete the magnetic circuit. The housing 40 may be provided with external peripheral threads, as shown, for mounting the relay unit in an appropriate chassis. The housing has an integral angular flange 40a at its upper end which is adjacent the outer surface of the wall 18 when the relay unit is assembled. The housing is held in the assembly by means of a nut 42 which is threaded on a threaded portion at the end of the tubular member 26. The end of the tubular member 26 may be protected by a cap 46 which is also threaded to the core (FIGURES 3 and 4).

An armature 50 is pivotally mounted on the upper surface of the wall 18 for angular movement in a plane perpendicular to that surface. The coil spring 52 is positioned under the armature, and the spring serves to bias the armature about its pivotal axis to an up position with respect to the wall 18.

The spring 52, as mentioned above, is relatively weak, and serves merely to bias the armature 50 to its upper position. Due to the construction of the relay, to be described, additional means are provided for moving the movable contact itself when the relay is de-energized, so that the armature spring 52 is relieved of that function. In a constructed embodiment of the invention, the armature spring 52 was constructed to exert a force of the order or 20 grams.

In a constructed embodiment, the relay was constructed so that the outer edge of the armature was 20 mils from the wall 18 when the relay was de-energized. When the rela-y was energized, the construction was such that the armature moves mils, so as to be still 10 mils away from the surface of the wall when the movable contact engages the normally-open iixed contact of the relay. This latter displacement provides for a positive bias of the movable contact against the normally-open ixed contact when the relay is energized.

An insulating rod S4 is mounted on the armature 50 by means, for example, by staking it through a hole in the armature. As mentioned above, the rod 54 may be composed of a suitable insulating material, such as polished sapphire.

The relay includes a movable contact 60 which, as best shown in FIGURE 5, is shaped to define a hollow rectangle. A rst bracket 62 is mounted, or formed integral with one end of the movable contact 60, this latter bracket is apertured, so that it can be staked to the lower end of the common relay terminal 12. A retainer clip 64 holds the movable contact 60 on the lower end of the terminal 12 for pivotal movement about the axis of the terminal 12. A second integral bracket 65 extends across the bottom of the movable contact 60, and the upper end of the rod 54 is received in a hole in the bracket 65.

A second spring 66 may be provided and this latter spring presses against the movable contact 60 normally to bias the contact against the terminal pin 14. It will be appreciated that the lower end of the terminal pin 14 serves as the normally-closed fixed contact of the relay, and the lower end of the terminal pin 16 serves as the normally-open fixed contact of the relay. A ball 67 is welded to the end of the spring 66 to facilitate operation of the assembly. The spring 66 is a relatively strong spring, and its function is to return the movable contact to the normally closed xed contact 14 when the relay is de-energized, so as to relieve the armature spring 52 of that function.

In the constructed embodiment of the invention, the spring 66 was made relatively strong, and capable of exerting a force, for example, of the order of 60 grams against the movable contact 60. The spring 66 is displaced towards the pivoted end of the movable contact, as shown in FIGURE 5, to provide as much space as possible between it and the xed contacts 14 and 16, so as to avoid arcing in the relay. The movable contact is constructed of a suitable electrically conductive material, such as heat treated beryllium copper.

When the relay is de-energized, the armature 50 is 'biased against the retainer 53, by the armature spring 50, and the movable contact 60 is biased against the normally-closed fixed contact 14 by the movable contact spring 66. When the relay is energized, the armature 50 is drawn down towards the wall 18, and the insulating rod 54 moves the movable contact 60 against the normallyopen xed contact 16.

The illustrated mounting of the xed and movable contacts, and the illustrated shapes of the contacts provide for a relatively large contact area, so as to achieve correspondingly low contact resistance. For example, the constructed embodiment exhibits a contact resistance of the order of .002 ohm, as compared with usual contact resistances of the order of .006 ohm, which are prevalent in the art.

The resilient mounting of the insulating rod 54 on the armature 50 by means of the resilient strip 56 provides, as mentioned above, for smooth operation of the relay, and permits the relay to be assembled without having to meet excessively close tolerances.

During the assembly of the relay, the movable contact 60 may be mounted in the envelope 10, together with the contact spring 66, as a separate unit, as shown in FIG- URE 4. Likewise, the other components of the relay may be mounted on the wall 18, as also shown in FIGURE 4. These components may be so mounted easily and conveniently, and adjusted. Then, the two parts of the relay can be brought together and welded, as a nal operating procedure, thus facilitating the fabrication of the unit. As mentioned above, the over-lapping stop retainer 53 establishes definite pull-in characteristics for the relay, in providing a denitely spaced gap between the armature 50 and the magnetic circuit of the relay when the relay is de-energized.

The particular shape of the movable contact 60 enables it to withstand high temperatures without distortion. Also, the use of the separate movable contact spring 66, as mentioned above, permits a weak armature spring 52 to be used, so that the relay has no tendency to bind, as was prevalent in the prior art.

While a particular embodiment of the invention has been shown and described, modifications may be made. The following claims are intended to cover all such modications which come within the scope of the invention.

What is claimed is:

1. In a vacuum relay which includes an envelope, a wall member of magnetic material atixed to said envelope and enclosing one end thereof, and a plurality of electrically conductive terminal pins extending through said envelope, the combination of: a fixed electrically conductive contact mounted within said envelope on one of said terminal pins; a movable electrically conductive contact pivotally mounted Within said envelope on a second of said terminal pins for pivotal movement in a plane essentially perpendicular to the axis of said second terminal pin for selective electrical engagement with said xed contact; an armature pivotally mounted on said wall member; and means mechanically coupling said armature to said movable contact to cause said movable contact to move in said plane angularly about the axis of said second terminal pin in and out of electrical engagement with said xed contact.

2. The combination of claim 1 in which said armature is mounted for pivotal movement in a plane perpendicular to the plane of pivotal movement of said movable contact; and which includes resilient means for biasing said armature in a first angular direction.

3. The combination of claim 2 and which includes further resilient means coupled to said movable contact for biasing said movable Contact away from said Xed contact.

4. The combination defined in claim 1 in which said coupling means is an insulating rod.

5. The combination of claim 4 in which said movable contact has a configuration defining a hollow rectangle having vertically disposed sides, and in which said insulating rod extends up through the bottom of said rectangle.

6. The combination defined in claim 5 in which said movable contact includes an integral bracket extending across the bottom of said rectangle and having an aper- UNITED STATES PATENTS 3,312,803 4/1967 Perry et al. 335-151X BERNARD A. GILHEANY, Primary Examiner. R. N. ENVALL, JR., Assistant Examiner.

U.S. C1. X.R. 

